[Ali Imran]

The thief on the cross was judged by faith alone and not works

The thief on the cross, if we want to believe that story, doesn't negate the command to be obedient to the Law.

The thief was about to die. He didn't have time to be obedient to the Law. In the Hadith, we have a similar story of a sinful man who was on his way to repentance but he died while on his way. Our prophet صلي الله عليه وسلم said he received salvation.